Flatheads and cooling question

[shaune]

I found out last fall that the 230 Chrysler flathead we ran all last hot summer didn't have a thermostat. The temp never climbed out of range in the guage on all our miles last summer, no condensation in the oil.....everything ran fine. So i was surprized when i found no thermostat.
The only problem i found was in the late fall the temp wouldn't come up to operating range......no big deal since we don't the car that late in the season.

SOOO, should i mess with something that works :D ?? Or leave well enough alone.
This makes me think that I have a cooling problem that the previous owner bandaid fixed by removing the thermostat.
Thoughts................

[dale48mrc]

You maybe right on the bandaid solution.I would say for peace of mind have the system pressure checked.The previous owner may have removed the thermostat to deal with a over heating problem.At least a pressure check of the cooling system will reveal any leaks,and if it's okay,put a 195 thermo for summer,cooler for the off season.Oh yea,buck up for the failsafe type!Just a little extra insurance fer yer mill!

[TinyTin]

Dale, I believe a 195 thermostat is for winter and the lower number like 165 would be for summer. If I am wrong get D_Jo to tune me up.
Don

[shaune]

Oh, another question is.........
the cooling system doesn't have a pressure cap, did some reading and maybe will try a 4 or 6 pound cap.
Thoughts...........

[johnny37]

Dale, I believe a 195 thermostat is for winter and the lower number like 165 would be for summer. If I am wrong get D_Jo to tune me up.
Don

195 degrees all year round never hurt anything. Cooler is not better, especially in the summer. The thermostat is used to regulate the flow of water to keep it at a given temperature. Once it reaches a temp of about 5 degrees over that temp, the thermostat is wide open, and no longer regulates anything. In the normal operation of your car, the thermostat will open a little, close a little, open a little more, close a little more, and on and on to keep the water at a given temp. So to put this in perspective, if you use a colder stat in the summer, almost all the time that stat is wide open and doing nothing to regulate the system. Hence it will do nothing to cure an overheating problem. A hotter stat will be able to regulate the water flow for the given temperature longer and with more success in terms of preventing overheating. Small blocks almost always use 195 degree themostats, and in fact the new cars run on 215 degree (or even a little higher) thermostats. Higher temps make for better emission control functions. A higher pressure rad cap is of no use to overheating problems, as the higher pressure is only to increase the boiling point of the water.

Shaune, if your cooling system is designed as a non pressurized system, the most you'll be able to run for a rad cap is 7 pounds. Anything higher and you'll split the rad tanks. Don't ask me how I know.;):rolleyes:

To answer your question for the flathead, my opinion is to put in a 180 or 195 degree themostat and see what happens. If it gets too hot, the band aid may be the way to go for the time being. I'm thinking Digger Dave the flathead guy may have something to say about this topic too. :D:D

[C Plus]

GREAT INFO , I am just trying to cure ,said issues ,I am thinking I should have it cured, thanks !

[Fopar]

I'm running a 180 thermostat in my 218 flathead 6 and it seems to work fine. Have no pressure cap but do have dual carbs, aluminum head and dual exhaust. Also running a PCV system that I cobbled up.

[dumprat]

If you can find one get a thermostat out of a military power wagon. They are a mulit stage set up. I had one in a 54 m37 and It worked flawlessly cold or hot weather. I sold all my spare parts though. Sorry.

[Kustomshoebox]

I run dual 185 fail safes in my 239 flatty... I also drilled a 1/8 hole in the retainer ring as per instruction in rodder magazine. 7 pound cap... stock was 4, and I was having cooling problems UNTILL ( thank you 'CherryMerc) I switched my hoses on my heater core... it must have some sort of one way valve in it, that was preventing it from cooling properly...


Runs good now though

[shaune]

Well now that the engine is coming out, the rad will be checked over and so will the heater core. Also the distributor tube in the head will be replaced and then i will know the cooling system will be problem free for some time.